The present invention relates to switching mechanisms for preparing fluidic output signals, in which a first converter or transformer acted upon by fluidic input signals is connected in circuit in front of an electrical system which makes the converted signals available after expiration of a time interval presettable on said system, or of an event value, in the form of a control signal.
In preparing control signals under the application of fluidic input signals, it is known to convert the fluidic input signal into an electrical signal and thereupon to feed the latter to a time function element which, in accordance with the preselected time interval, makes an electrical output signal available as a control signal. The latter may then, for example, be fed to the electromagnetic valve of a fluidic switching circuit which is to be controlled. For more protracted periods, e.g., several minutes or hours, time function elements of this nature comprise mechanical retarding mechanisms or systems operated by centrifugal force. For shorter periods, it is known that a component operating in accordance with the inductance-capacitance principle may be utilized as a time function element. Time function elements of this kind have the disadvantage that, apart from considerable mechanical complexity, they do not work with precise timing, that is to say, in respect of the onset as well as of the duration of the period required in each case. This also applies regarding the reproducibility of the timing settings. These time function elements are moreover affected by hysteresis and parallax.
time function elements of the transistor or quartz type are installed, for example, in radio apparatus or in digital clocks that include automatic alarms. These time function elements, which operate very precisely, have not as yet been applied in controlling and governing operations in the sphere of fluidics.
Finally, counter elements are utilized in fluidics which do not transmit a control signal to a post-connected system until after several actions counted as events at their input side.
It is an object of the invention to provide a switching mechanism for the preselectible preparation of fluidic output signals as control signals, which allows optional presetting of a time or event value, which, despite uncomplicated structure, allows a precise reproducible presetting of the onset as well as of the duration of the signals which are to be prepared, and assures these qualities for an extremely great number of hours of operation and may be operated on very low electrical power.